Devoir de Philosophie

Andes - geography.

Publié le 26/05/2013

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Andes - geography. I INTRODUCTION Andes, the principal mountains of South America and one of the greatest mountain systems of the world. The Andes include some of the world's highest peaks. More than 50 of them soar higher than 6,100 m (20,000 ft) above sea level. Only the Himalayas of south central Asia are higher. The lofty plateaus and high mountain valleys of the Andes contain some of the highest permanent human settlements in the world. The Andes are the longest system of high mountain ranges on earth. They extend for more than 8000 km (5000 mi) in a narrow belt along the western edge of the South American continent, from the coast of the Caribbean Sea in the north to the island of Tierra del Fuego in the extreme south. Along almost its entire length, the Andes rise abruptly from the Pacific coast. The mountains reach into seven countries: Venezuela, Colombia, Ecuador, Peru, Bolivia, Chile, and Argentina. The Andes formed during the Cretaceous period (about 138 million to about 65 million years ago) when the Pacific crustal plate began to slowly slide beneath the South American plate, uplifting and folding the sedimentary rocks that comprise the Andes (see Plate Tectonics). Tectonic forces generated by this collision still trigger earthquakes and volcanic eruptions. Within the range are lofty plateaus, such as the plateau of Quito (about 3,000 m/about 10,000 ft) in Ecuador and that of Lake Titicaca (4,000 m/13,000 ft) in southern Peru and Bolivia. II THE PRINCIPAL RANGES OF THE ANDES The mountain belt is generally about 300 km (about 200 mi) wide, except in Bolivia, where it expands to twice that width. From north to south the belt can be divided into three regions: a northern section in Venezuela, Colombia, and northern Ecuador; a central section in southern Ecuador, Peru, Bolivia, and the northern regions of Argentina and Chile; and a southern section in the southern regions of Argentina and Chile. The northern Andes curve in an arc from northeast to southwest. The arc consists of...

« The most important native domestic animal of the Andes is the llama, a member of the same family as the camel.

The llama, found predominantly in Peru and Bolivia, canlive at high altitudes.

It is used as a beast of burden and yields wool, milk, and meat.

The alpaca, an animal related to the llama, is raised for its wool.

Wild animals includethe vicuña, which is another member of the camel family, and the chinchilla, which is a member of the rodent family.

Both the vicuna and the chinchilla are prized for theirpelts.

The birds of the Andes include the condor, the largest of all birds of prey. VII ECONOMIC ACTIVITIES AND HUMAN SETTLEMENT The Andes are rich in mineral deposits, including gold, silver, copper, platinum, mercury, lead, iron ore, petroleum, and sulfur.

Indigenous people mined gold and silverprior to the Spanish conquest of the area in the 16th century.

Today, copper is mined in Chile and Peru, and antimony and tin are mined in Bolivia.

Many of the mines aremore than 4,600 m (15,000 ft) above sea level.

Some farming is carried on at high altitudes, especially in the Altiplano, where grain and potatoes are grown at about 3,700to 4,000 m (about 12,000 to 13,000 ft) above sea level.

Sheep, alpacas, and llamas are pastured on the high mountain slopes.

Tourism is also a major source of revenue insome areas, such as in Peru where tourists visit the ancient cities of Machu Picchu and Cuzco.

These sites were constructed by the Incas, a pre-Colombian people who builtan extensive civilization extending from central Chile to northern Ecuador. Settlements in the high Andes include La Paz, which is the seat of government of Bolivia, and Quito, which is the capital of Ecuador.

La Paz, which is about 3,600 m (about11,900 ft) above sea level, is the highest large city in the world.

Cuzco, Peru, was the capital of the ancient empire of the Incas and is the capital of one of Peru’s 25governmental departments.

For centuries parts of the Andes have been densely populated by indigenous farmers and herdsmen.

Today many indigenous people live andwork in much the same way as their ancestors did under the rule of the Incas and, later, of Spanish colonists.

Crops are often planted on hillside terraces, constructed totake advantage of scarce agricultural land located on steep terrain. Microsoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation.

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